// Copyright 2016 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Functions for creating prediction schemes for encoders using the provided
// prediction method id.

#ifndef DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_ENCODER_FACTORY_H_
#define DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_ENCODER_FACTORY_H_

#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_constrained_multi_parallelogram_encoder.h"
#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_geometric_normal_encoder.h"
#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_multi_parallelogram_encoder.h"
#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_parallelogram_encoder.h"
#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_tex_coords_encoder.h"
#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_tex_coords_portable_encoder.h"
#include "draco/compression/attributes/prediction_schemes/prediction_scheme_delta_encoder.h"
#include "draco/compression/attributes/prediction_schemes/prediction_scheme_encoder.h"
#include "draco/compression/attributes/prediction_schemes/prediction_scheme_factory.h"
#include "draco/compression/mesh/mesh_encoder.h"

namespace draco {

// Selects a prediction method based on the input geometry type and based on the
// encoder options.
PredictionSchemeMethod SelectPredictionMethod(int att_id,
        const PointCloudEncoder *encoder);

// Factory class for creating mesh prediction schemes.
template <typename DataTypeT>
struct MeshPredictionSchemeEncoderFactory {
    template <class TransformT, class MeshDataT>
    std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>> operator()(
                PredictionSchemeMethod method, const PointAttribute *attribute,
                const TransformT &transform, const MeshDataT &mesh_data,
    uint16_t bitstream_version) {
        if (method == MESH_PREDICTION_PARALLELOGRAM) {
            return std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>(
                       new MeshPredictionSchemeParallelogramEncoder<DataTypeT, TransformT,
                       MeshDataT>(
                           attribute, transform, mesh_data));
        } else if (method == MESH_PREDICTION_MULTI_PARALLELOGRAM) {
            return std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>(
                       new MeshPredictionSchemeMultiParallelogramEncoder<
                       DataTypeT, TransformT, MeshDataT>(attribute, transform,
                               mesh_data));
        } else if (method == MESH_PREDICTION_CONSTRAINED_MULTI_PARALLELOGRAM) {
            return std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>(
                       new MeshPredictionSchemeConstrainedMultiParallelogramEncoder<
                       DataTypeT, TransformT, MeshDataT>(attribute, transform,
                               mesh_data));
        } else if (method == MESH_PREDICTION_TEX_COORDS_DEPRECATED) {
            return std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>(
                       new MeshPredictionSchemeTexCoordsEncoder<DataTypeT, TransformT,
                       MeshDataT>(
                           attribute, transform, mesh_data));
        } else if (method == MESH_PREDICTION_TEX_COORDS_PORTABLE) {
            return std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>(
                       new MeshPredictionSchemeTexCoordsPortableEncoder<
                       DataTypeT, TransformT, MeshDataT>(attribute, transform,
                               mesh_data));
        } else if (method == MESH_PREDICTION_GEOMETRIC_NORMAL) {
            return std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>(
                       new MeshPredictionSchemeGeometricNormalEncoder<DataTypeT, TransformT,
                       MeshDataT>(
                           attribute, transform, mesh_data));
        }
        return nullptr;
    }
};

// Creates a prediction scheme for a given encoder and given prediction method.
// The prediction schemes are automatically initialized with encoder specific
// data if needed.
template <typename DataTypeT, class TransformT>
std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>
        CreatePredictionSchemeForEncoder(PredictionSchemeMethod method, int att_id,
                const PointCloudEncoder *encoder,
const TransformT &transform) {
    const PointAttribute *const att = encoder->point_cloud()->attribute(att_id);
    if (method == PREDICTION_UNDEFINED) {
        method = SelectPredictionMethod(att_id, encoder);
    }
    if (method == PREDICTION_NONE)
        return nullptr;  // No prediction is used.
    if (encoder->GetGeometryType() == TRIANGULAR_MESH) {
        // Cast the encoder to mesh encoder. This is not necessarily safe if there
        // is some other encoder decides to use TRIANGULAR_MESH as the return type,
        // but unfortunately there is not nice work around for this without using
        // RTTI (double dispatch and similar concepts will not work because of the
        // template nature of the prediction schemes).
        const MeshEncoder *const mesh_encoder =
            static_cast<const MeshEncoder *>(encoder);
        auto ret = CreateMeshPredictionScheme<
                   MeshEncoder, PredictionSchemeEncoder<DataTypeT, TransformT>,
                   MeshPredictionSchemeEncoderFactory<DataTypeT>>(
                       mesh_encoder, method, att_id, transform, kDracoMeshBitstreamVersion);
        if (ret)
            return ret;
        // Otherwise try to create another prediction scheme.
    }
    // Create delta encoder.
    return std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>(
               new PredictionSchemeDeltaEncoder<DataTypeT, TransformT>(att, transform));
}

// Create a prediction scheme using a default transform constructor.
template <typename DataTypeT, class TransformT>
std::unique_ptr<PredictionSchemeEncoder<DataTypeT, TransformT>>
        CreatePredictionSchemeForEncoder(PredictionSchemeMethod method, int att_id,
const PointCloudEncoder *encoder) {
    return CreatePredictionSchemeForEncoder<DataTypeT, TransformT>(
               method, att_id, encoder, TransformT());
}

// Returns the preferred prediction scheme based on the encoder options.
PredictionSchemeMethod GetPredictionMethodFromOptions(
    int att_id, const EncoderOptions &options);

}  // namespace draco

#endif  // DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_ENCODER_FACTORY_H_
